THIS INVENTION relates to an airship. It relates also to a modular unit for forming an airship.
According to a first aspect of the invention there is provided, a modular unit for forming an airship, the modular unit including
an elongate spine intended to extend along a longitudinal axis of the airship, the spine including at least one interconnecting element having connection means for joining it in end to end relationship with an interconnecting element of an adjacent modular unit; and
buoyant support means fixed relative to the spine for providing buoyant support to the airship, in flight.
The buoyant support means may be in the form of at least one gas bag. The gas bag may be filled with helium for displacement of air, which provides the buoyant support for the airship. Typically, the unit may include a frame assembly for supporting the bag around the spine.
In one embodiment of the invention, the frame assembly may include at least one support ring which is positioned in radially spaced relationship relative to the spine intermediate leading and trailing extremities of the spine thereby defining an annular space between the spine and the ring into which the gas bag is received.
The frame assembly may further include a plurality of elongate locating members which are fixed at circumferentially spaced positions to the ring and which extend inwardly from the ring towards the spine. Thus, the locating members serve fixedly to position the ring relative to the spine.
The locating members may extend bicycle-spoke fashion between the ring and the leading and trailing extremities of the spine thereby defining a pair of back to back frusto-conical spaces around the spine for receiving the gas bag. The locating members may be in the form of flexible strands and may be connected in tension between the ring and the spine.
The unit may further include tension relaxing means for relaxing over-tensioning of the flexible strands induced by relative limited movement of adjacent interconnected elements when the airship is in flight.
In particular, inner ends of the flexible locating members may be fixed to a pair of spaced inner rings located in close proximity to the spine at leading and trailing extremities thereof. The inner rings may then be slidable longitudinally relative to the spine and may each have biassing springs connectable to similar inner rings of an adjacent modular unit thereby to bias the inner rings in opposite directions to form the tension relaxing means.
In another embodiment of the invention, the locating members may be rigid and may extend radially outwardly from the spine thereby dividing the unit in a circumferential direction into a number of segments.
A plurality of gas bags may be secured to the rigid locating members and may, once filled occupy each of the segments. In one embodiment, each modular unit may include four locating members circumferentially spaced at 90xc2x0 to one another and dividing the unit into quadrants, each quadrant being occupied by a bag.
At least one of the rigid locating members may include a plurality of struts extending outwardly from the rectangular support and defining a cage-like housing for receiving one of the gas bags. Accordingly, in addition to the bags which occupy the quadrants between successive locating members, further bags may be provided formed within the housing of one or more of the rigid locating members. Typically, when the modular unit is divided into quadrants by four rigid locating members, an upwardly and downwardly extending locating member may define first and second housings for receiving a bag, in addition to the four bags provided in each of the quadrants.
In another embodiment, the gas bags may be located within the frusto conical spaces referred to above and/or in the space outside of the frusto-conical spaces.
The upwardly extending first housing may have a flat upper surface which when each of the modular units of the mid-section are joined together, is aligned with corresponding flat upper surfaces of adjacent mid-sections, thereby providing a walkway along a top portion of the airship.
The spine may define an inner longitudinally extending passage which extends along the length of the spine. In one embodiment, the spine may include a plurality of struts joined together to form a box-like rectangular support extending along the longitudinal axis. The struts may be joined together to form a box-like support of triangular or similar cross-section. In another embodiment, the spine may be generally circular cylindrical in shape defining a circular passage along its length.
The invention extends also to an airship which includes
a central spine extending along a longitudinal axis of the airship for providing rigidity to the airship;
a frame assembly attached to and surrounding the spine; and
buoyant support means fixed relative to the spine for providing buoyant support to the airship, in flight.
The airship may be formed from a plurality of modular units as above described.
The modular units may be cylindrical in cross-section. In one embodiment, a mid-section of the airship may be cylindrical and may include a plurality of cylindrical modular units which are interconnected end to end. Similarly, nose and tail sections of the airship may include a plurality of cylindrical modular units connected end to end with the cross-sectional area of each unit decreasing from each of the ends of the cylindrical mid-section to the outer extremities of the nose and tail sections, respectively. Instead, the nose and tail sections may each comprise a single modular unit.
The overall shape of the airship may also be elliptical in side elevation.
Each of the modular units may be connected to an adjacent modular unit by connection means. More particularly, ends of each of the spines may be fastened together, for example, by means of nuts and bolts.
The airship may further include a gondola having releasable attachment means for releasably attaching the gondola to the airship.
In one embodiment, when the frame assembly defines the annular space, the gondola may be received within at least a portion of the annular space defined around the spine. The gondola may have an arcuately shaped outer surface which is flush with an outer surface of the airship.
In another embodiment, the downwardly extending second housing may include a lower flat surface which when each of the modular units of the mid-section are joined together, is aligned with corresponding flat lower surfaces of adjacent mid-sections for providing an area of attachment for a roof section of the gondola. In another embodiment, each modular unit of the mid-section may include a portion of the gondola attached to its lower flat surface, an end of each portion of the gondola then being secured to an abutting end of a portion of the gondola of an adjacent modular unit. The gondola may thus be formed from a plurality of modular gondola units capable of being joined in end to end relationship.
The bag may be of any suitable lightweight material, for example, parachute silk or material sold under the trade name Tedlar or Ripstop. The struts and locating members may be made of any suitable lightweight structural material, for example, aluminium. The spine may be made of any resilient lightweight material, for example, carbon fibre composite material.
Each of the bags may be secured together in any suitable manner. More particularly, each bag may be secured adhesively to an adjacent bag, for example, by means of adhesive means sold under the trade name Velcro and may be fastened to one or more of the struts by means of, for example, rubber grommets. More particularly, each of the bags may include an extended seam portion defining a plurality of apertures along a length thereof and may then be fastened, for example, by means of the rubber grommets along a length of an adjacent strut. When the locating members are in the form of flexible strands, the bags may be fixed relative to the spine by being secured to the spine and/or the rings.
The airship may have a flexible outer skin which at least partially surrounds the interconnecting modular units, thereby providing a continuous exterior surface which may be used for placing advertisements and the like on the airship.
The airship may be mechanically driven. More particularly, the airship may be provided with at least one engine or electric motor for driving one or more propellers situated toward the outer extremity of the tail section. When the airship has an engine one or more of the modular units may be provided with fuel storage tanks. The propellers may direct air over a ruddervator to permit moving of the airship vertically and horizontally even while the airship is not moving or is travelling at low speeds.
In another embodiment, the airship may be externally driven. In particular, it may have attachment means for attaching it to a ground vehicle, for example, by means of a cable.
The airship may include control means for controlling the direction of flight of the airship. In particular, the control means may be in the form of one or more rudders provided on the tail section. The airship may also include tanks for containing ballast, e.g. water and compressed air, and release means for releasing the ballast thereby to permit control of the elevation of the airship.
The airship may be provided with instrumentation, fuel lines and the like which pass through more than one modular unit. Accordingly, each modular unit may be fitted with sections of the instrumentation, fuel lines and the like for connecting to corresponding sections on adjacent modular units.
The spine may define an air tight conduit for receiving the compressed air. The spine may also be provided with air release ports for releasing the air from the conduit thereby to permit the direction of movement of the airship to be controlled.